Holder for sharpening twist drills

ABSTRACT

A holder for sharpening twist drills wherein the drill rests between sets of rollers mounted on a pair of parallel shafts. The shafts form part of a frame which pivots a limited amount about an axis perpendicular to the axis of the drill. A clamp is secured to the drill, and is provided with diametrically disposed shafts either one of which is insertable between a pair of fixed rods underlying the rollers which cause the drill to turn on its axis as the frame is moved arcuately. An adjustable stop controls the axial position of the drill. A modification involves the use of a slotted V-guide.

United States Patent [72] Inventor William C. Reynolds P.O. Box 403.Morro Bay. Calif. 93442 [21] Appl. No. 865,629 [22] Filed Oct. 13. 1969[45] Patented July 27. i971 [54] HOLDER FOR SHARPENING TWIST DRILLS 14Claims, 8 Drawing Figs.

[52] U.S.Cl 51/219R [51] Int. Cl B24b 3/26 [50] Field ofSearch 51/219 R,219 PC [56] References Cited UNITED STATES PATENTS 153,40l 7/1874 Haagen51/219 Primary Examiner-Harold D. Whitehead Attorney-Lyon & LyonABSTRACT: A holder for sharpening twist drills wherein the drill restsbetween sets of rollers mounted on a pair of parallel shafts. The shaftsform part of a frame which pivots a limited amount about an axisperpendicular to the axis of the drill A clamp is secured to the drill,and is provided with diametrically disposed shafts either one of whichis insertable between a pair of fixed rods underlying the rollers whichcause the drill to turn on its axis as the frame is moved arcuately. Anadjustable stop controls the axial position of the drill. A modificationinvolves the use ofa slotted V-guide.

HOLDER FOR SHARIENING TWIST DRILLS SUMMARY OF THE INVENTION Thisinvention is summarized in the following objects: First. to provide aholder for sharpening twist drills which is inexpensive yet capable ofpresenting the drill to the grind wheel in such a manner that the twoend faces, when finished, are identical with identical cutting edgeangles and clearance angles, even when operated by unskilled persons.

Second, to provide a holder for sharpening twist drills which is readilyadjusted to change the clearance angle of the drill to meet differentdrilling conditions.

Third, to provide a holder for sharpening twist drills which is capableof handling a wide range of drill sizes.

Fourth, to provide a holder for sharpening twist drills which utilizes asupport defining a V-groove in which the drill or a shaft coaxialtherewith is placed; the support providing openings through which across shaft secured to the drill or its coaxial shaft extends; thesupport being movable as a unit with the drill about an axisperpendicular to the drill and an end of the cross-shaft engaging afixed member so that, on movement of the drill about the perpendicularaxis, the drill is rotated about its axis thereby to generate aclearance angle.

Fifth, to provide a holder, as indicated in the preceding object,wherein the supports and drill are adjustable radially with respect tothe perpendicular axis which includes novel means to effect preciseaxial adjustment of the drill in radial relation to the perpendicularaxis.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the holder forsharpening twist drills, with a portion of the grind wheel shown insection, the holder being shown in its initial or starting position bysolid lines, and in its final position by dotted outline.

FIG. 2 is a side view of the holder, the parts being shown in theirmidposition.

FIG. 3 is a transverse sectional view, taken through 3-3 of FIG. 2.

FIG. 4 is a fragmentary sectional view, taken through 4-4 of FIG. 2.

FIG. 5 is a plan view, similar to FIG. 1, showing a modifiedconstruction of the holder.

FIG. 6 is a sectional view, taken through 6-6 of FIG. 8.

FIG. 7 is a fragmentary sectional view thereof, taken through 7-7 ofFIG. 8.

FIG. 8 is a transverse sectional view, taken through 8-8 of FIG. 6.

Reference is first directed to FIGS. 1 through 4. The holder forsharpening twist drills includes a base 1 in the form of a rectangularplate. Extending upwardly from one end of the base is a journal post 2which receives a pivot shaft 3. The upper end of the pivot shaft isjoined to a crossbar 4.

Secured to the crossbar 4 and extending horizontally therefrom is a pairof parallel roller journal rods 5 and an adjustment rod 6 parallel tothe journal rods. The extremities of the rods 5 and 6 are joined to asecond crossbar 7. Extending downward from the crossbar 7 is asupporting shaft 8, the lower end of which rides on the base 1. Mountedon or forming a part of the base I is a stop member 9 in the form ofaboss having an arcuate side terminating in stop ends 10 adjacent eachside margin ofthe base 1.

Each journal rod 5 receives a set of rollers II. The rollers of each setare axially movable on their respective journal rod. The rods are spacedsuch that the rollers of each set are contiguous to the rollers of theother set but do not quite touch. The rollers form a channel to receivea twist drill l2, and is intended to accommodate drills ofdifferentdiameter, for example, ranging from a sixteenth ofan inch in diameter toa half of an inch in diameter. The holder may, however, be adapted forlarger or smaller drills.

The journal rods 5 are positioned equidistant at opposite sides of thevertical pivotal axis of the frame comprising the crossbar 4, journalrods 5, adjustment rod 6, and crossbar 7. As a consequence, the axis ofrotation of the drill rod intersects the vertical pivotal axis of theframe.

The adjustment shaft 6 is screw threaded to receive a roller positioningwheel 13, which is engaged by a spring 14 to provide sufficient frictionin order that the positioning wheel will remain wherever it may beplaced. The positioning wheel engages the first roller of the adjacentset of rollers so that forward movement of this set of rollers towardthe grind wheel may be determined by the positioning wheel 13.

A drill clamp is provided. The drill clamp is provided with an opening16, forming a V-end, and is intended to receive a drill. The drill clampis screw threaded to receive a screw shaft 17 which bears against adrill within the opening 16 so as to press the drill into the V-endthereof. A second shaft 18, in coaxial alignment with the screw shaft17, extends in a diametrically opposite direction. By spreading therollers axially, either shaft 17 or 18 of the drill clamp may beextended between the rollers and toward the base I.

The base 1 is provided with a boss 19, located near the end of the baseopposite from the journal post 2. The boss 19 is offset laterally withrespect to the pivot shaft 3 and supporting shaft 8. Pivotally supportedfrom the boss 19 for movement about a common axis is a pair of parallelbars 20, which slope upwardly and forwardly toward the pivot shaft 3.The bars are spaced to receive the tip of either shaft 17 or 18, asindicated in FIG. 3.

Operation of the holder for sharpening twist drills shown in FIGS. 1through 4 is as follows:

The holder is positioned with respect to a grind wheel 21 so that thegrinding surface of the grind wheel coincides with a vertical or pivotalaxis of the frame. A drill l2, placed between the sets of rollers isthus positioned so that its axis intersects the grind wheel at a pointcommon to the axis of rotation of the frame.

The drill clamp 15 is secured to the drill and the rollers II are spreadaxially so as to form a slot through which the drill clamp and one ofits shafts may extend downwardly for insertion between the parallel bars20. The positioning wheel 13 is adjusted so that the surface of thedrill is brought into contact with the grind wheel. The initial positionis shown in FIG. 1 in which the supporting shaft 8 is in engagement withone of the stop members 9. When the frame and the drill 12 are movedfrom the position shown by solid lines in FIG. 1 toward the dottedoutline position, the drill is caused to rotate around its axis. As aresult, a drill face is generated and the drill face forms apredetermined clearance angle. During this operation, the drill is heldin place by the operators hand. Between grinding operations, theposition of the drill is changed by reversing the position of the drillclamp and inserting the other shaft between the bars 20.

The location of the drill clamp varies depending upon the length ofdrill; that is, the drill clamp is closer to the pivoted end of theframe when secured to a smaller drill. The slope of the bars 20 tend tocompensate for location of the drill clamp so that whether a short drillor a long drill is being ground, the rotation of the drill and hence theclearance angle tend to remain constant.

It should be observed that while in most cases the axis of rotation ofthe frame coincides with the surface of the grind wheel, the holder maybe displaced to change the configuration of the end face of the drill.Also, the angular relation of the holder with respect to the grind wheelmay be altered should this be desired.

Reference is now directed to FIGS. 5 through 8. The construction hereillustrated includes many parts of the .firstdescribed structure, whichbear corresponding reference characters. The modified constructionincludes a baseplate 22, which rests on a table 23, and is capableofannular adjustment. This is accomplished by extending the journal post2 through the baseplate 22 to form a pivot 24, and securing the journalpost to the table 23. The opposite end of the baseplate 22 is providedwith a slot 25 which receives a clamp screw 26 extending into the table23.

In place ofthe fixed stop 10, an adjustable stop 27 is provided. Theadjustable stop includes a boss 28, extending upward from the baseplate22. The boss 28 receives a horizontally extending screw shaft 29 whichis provided with an adjustment wheel or knob 30 so that the screw shaftmay be advanced or retracted endwise. Mounted on the screw shaft is apair of stop discs 31, which may be adjustably secured by nuts 32. Thestop discs 31 engage the supporting shaft 8 to limit its arcuatemovement.

The pivot shaft 3 and frame which included the crossbars 4 and 7 and therods 5 and 6 of the previously described structure are utilized, thechange ifany being one merely ofdimension. In place of the rollers 11,the frame receives a carriage 33, having end bars 34 provided withslotted ends which receive the rods 5. The end bars 34 are connected bya V- guide member 35, having a series of slots 36 therein.

The positioning wheel 13 and spring 14 of the firstdescribed structureare utilized and includes a finger 37, which engages the carriage in thesame manner that the wheel 13 of the first-described structure engagesone of the rollers.

The cartridge 33 may support a drill 12 directly as in the firstdescribed structure and utilize the drill clamp 15. Alternatively, theV-guide member 35 may support a journal shaft 38, provided with a crossrod 39 which serves the function of the drill clamp 15 and its shafts l7and 18. A chuck 40 is secured to one end of the journal shaft 38 andreceives the drill 12 to be sharpened. The end of the journal shaft 38opposite from the chuck 40 may be provided with a counterbalance 41.

In place of the boss 19 and the parallel bars 20 of the firstdescribedstructure, there is provided a drill turning lever 42, mounted on thebaseplate 22 by means ofa pivot 43. The lever 42 includes a first arm44, terminating in an end slot 45 which straddles the supporting shaft8. The lever includes a second arm 46, the portion of which adjacent thepivot 43 extends upwardly so that the remaining portion may slopedownwardly, as shown in FIG. 7. The downwardly sloping portion of thesecond arm is provided with a slot 47 which receives either end of thecross rod 39 or if the drill clamp 15 is used, either shaft 17 or 18 isreceived by the slot 47.

, Operation of the construction shown in FIGS. 5 through 8 isessentially the same as the firstdescribed structure. The drillturninglever 42 operates essentially the same as the parallel bars 20. Becauseof the pivotal mounting of the lever 42, the second arm 46 and its slot47 which is the equivalent of the parallel bars 20 need to slopedownward toward the pivotal axis of the baseplate 22, rather thanupwardly. If desired, the lever 42 may be provided with more than onepivotal axis by providing more than one hole to receive the pivot 43.

The present embodiments of this invention are to be considered in allrespects as illustrative and not restrictive.

lclaim:

1. Means for holding twist drills for presentation to a grind wheel,comprising:

a. a frame having a pivotal axis located adjacent a grind wheel, theframe adapted for limited arcuate movement about its pivotal axis;

b. holding means carried by the frame defining a channel adapted toreceive and support a drill with its longitudinal axis intersecting thepivotal axis of the frame and permitting rotation of the drill about itsaxis; said holding means forming transverse openings;

c. drill turning means adapted to be secured to the drill and to extendradially through the openings;

d. and means engaging the turning means to effect turning of the drillabout its axis in correspondence with movement ofthe frame about itsaxis.

2. A twist drill holding means, as defined in claim 1,

wherein:

a. the holder means includes a pair of guide shafts and two sets ofguide rollers slidable on the shafts to provide the openings for thereceiving of the drill turning means. 3. A twist drill holding means, asdefined in claimv l,

' wherein:

a. the holder means is in the form of a fixed V-channel slotted atintervals to receive the drill turning means.

4. A twist drill holding means, as defined in claim 1, which furthercomprises:

a. means for longitudinally adjusting the holding means and drill withrespect to the grind wheel.

5. A twist drill holding means, as defined in claim 1,

wherein:

a. said frame includes a pair of parallel journal rods;

b. and said holding means includes sets of axially separable rollersmounted on said journal rods and forming said channel therebetween.

6. A twist drill holding means, as defined in claim 1,

wherein:

a. said frame includes a pair of parallel guide rods;

b. and said holding means includes a transversely slotted V- structure,the slots therein adapted to admit the drill turning means.

7. A twist drill holding means, as defined in claim 1,

wherein:

a. a base supports said frame;-

b. and the means engaging the turning means includes means forming aguide slot for receiving an end of said turning means therebetween.

8. Means for holding twist drills for presentation to a grind wheel,comprising:

a. a base member;

b. a vertical journal post at one end thereof;

c. a frame including a pair of guide bars and cross members at the endsthereof;

d. a member pivotally connecting one ofsaid cross members to the journalpost;

e. a supporting post extending from the other crossmember to the basefor arcuate movement thereon;

f. stop means for limiting the movement of the supporting post;

g. guide means axiallyslidable on the guide bars and defining anupwardly facing V-slot for rotation of a drill about its axis; saidguide means having at least one transverse opening;

h. drill turning means having opposed arms selectively insertablethrough the transverse opening;

i. and means supported from the base for receiving either end of theopposed arms, thereby to turn the drill about its axis as the frame ispivoted about its axis.

9. A holder, as defined in claim 8, wherein:

a. said guide means is a set of rollers disposed in pairs.

10. A holder, as defined in claim 8, wherein:

a. said guide means is a V-block.

11. A holder, as defined in claim 8, wherein:

-a. said drill turning means is a clamp attachable directly to a drill.

12. A holder, as defined in claim 8, wherein:

a. said drill turning means includes a chuck for clamping a drill, ashaft secured to the chuck in coaxial relation to the drill, the opposedarms being carried by the shaft.

13. A holder, as defined in claim 8, wherein:

a. said receiving means is fixed to the base member, slopes upwardlytoward the pivoted end of the frame, and defines a slot receiving aselected opposed arm.

14. A holder, as defined in claim 8, wherein:

a..said receiving means is pivotally connected to the base memberintermediate its ends, and includes a first end engaged by thesupporting post and a second end sloping downward toward the pivoted endof the frame, said second end defining a slot receiving a selectedopposed arm.

1. Means for holding twist drills for presentation to a grind wheel,comprising: a. a frame having a pivotal axis located adjacent a grindwheel, the frame adapted for limited arcuate movement about its pivotalaxis; b. holding means carried by the frame defining a channel adaptedto receive and support a drill with its longitudinal axis intersectingthe pivotal axis of the frame and permitting rotation of the drill aboutits axis; said holding means forming transverse openings; c. drillturning means adapted to be secured to the drill and to extend radiallythrough the openings; d. and means engaging the turning means to effectturning of the drill about its axis in correspondence with movement ofthe frame about its axis.
 2. A twist drill holding means, as defined inclaim 1, wherein: a. the holder means includes a pair of guide shaftsand two sets of guide rollers slidable on the shafts to provide theopenings for the receiving of the drill turning means.
 3. A twist drillholding means, as defined in claim 1, wherein: a. the holder means is inthe form of a fixed V-channel slotted at intervals to receive the drillturning means.
 4. A twist drill holding means, as defined in claim 1,which further comprises: a. means for longitudinally adjusting theholding means and drill with respect to the grind wheel.
 5. A twistdrill holding means, as defined in claim 1, wherein: a. said frameincludes a pair of parallel journal rods; b. and said holding meansincludes sets of axially separable rollers mounted on said journal rodsand forming said channel therebetween.
 6. A twist drill holding means,as defined in claim 1, wherein: a. said frame includes a pair ofparallel guide rods; b. and said holding means includes a transverselyslotted V-structure, the slots therein adapted to admit the drillturning means.
 7. A twist drill holding means, as defined in claim 1,wherein: a. a base supports said frame; b. and the means engaging theturning means includes means forming a guide slot for receiving an endof said turning means therebetween.
 8. Means for holding twist drillsfor presentation to a grind wheel, comprising: a. a base member; b. avertical journal post at one end thereof; c. a frame including a pair ofguide bars and cross members at the ends thereof; d. a member pivotallyconnecting one of said cross members to the journal post; e. asupporting post extending from the other crossmember to the base forarcuate movement thereon; f. stop means for limiting the movement of thesupporting post; g. guide means axially slidable on the guide bars anddefining an upwardly facing V-slot for rotation of a drill about itsaxis; said guide means having at least one transverse opening; h. drillturning means having opposed arms selectively insertable through thetransverse opening; i. and means supported from the base for receivingeither end of the opposed arms, thereby to turn the drill about its axisas the frame is pivoted about its axis.
 9. A holder, as defined in claim8, wherein: a. said guide means is a set of rollers disposed in pairs.10. A holder, as defined in claim 8, wherein: a. said guide means is aV-block.
 11. A holder, as defined in claim 8, wherein: a. said drillturning means is a clamp attachable directly to a drill.
 12. A holder,as defined in claim 8, wherein: a. said drill turning means includes achuck for clamping a drill, a shaft secured to the chuck in coaxialrelation to the drill, the opposed arms being carried by the shaft. 13.A holder, as defined in claim 8, wherein: a. said receiving means isfixed to the base member, slopes uPwardly toward the pivoted end of theframe, and defines a slot receiving a selected opposed arm.
 14. Aholder, as defined in claim 8, wherein: a. said receiving means ispivotally connected to the base member intermediate its ends, andincludes a first end engaged by the supporting post and a second endsloping downward toward the pivoted end of the frame, said second enddefining a slot receiving a selected opposed arm.